Study on Rockmass Deterioration Model Based on the Unified Strength Theory

Abstract:

Strain softening model;Unified strength theory;Rockmass deterioration model;FLAC3D Abstract:Aiming at the problem that traditional elasto-plastic constitutive models have not been successful in predicting the depth and extent of brittle failed of hard rocks under high geo-stress condition, a new rockmass deterioration model(RDM) based on the unified strength theory is put forward in the basis of strain softening model and cohesion weaking and friction strengthening (CWFS)model. In the new model, the influence of intermediatemain stress to characteristic of rockmechanics is considered. Based on the method of lagrangian finite difference, a finite difference format of unified strain- softening elastoplastic model with strength parameters of c and φ is established. The constitutive unified elastoplastic model is imported into FLAC3D using a dynamic-link library file developed by VC++.Based on the new model, the traditional triaxial tests (with different confining pressure) and true triaxial tests (with intermediate principal stress ratio) are simulated in FLAC3D, and the measured data are compared with the results that are are simulated by strain softening model and CWFS model. The analytic results suggest that the rockmass deterioration model based on the twin shear unified strength theory has more strong applicability

• Periodical: Advanced Materials Research (Volumes 468-471)
• Pages: 2521-2527
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.468-471.2521
• Online since: February 2012
• Authors: Xue Ying Zhang
• Keywords: FLAC^3D, Rockmass Deterioration Model, Strain Softening Model, Unified Strength Theory

References

[1] YANG mijia,HE Yongnian,ZHANG Nong.The law of surrounding rock strength decreasing and its dynamic supporting technology[J].Engineering Mechanics,1999,16(5):53-57.(in Chinese)

[2] HE Manchao,XIE Heping,PENG Suping,er al.Study on rock mechanics in deep mining engineering[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(16):2803-2813.(in Chinese)

[3] ZHOU Huoming, SEHNG Qian,LI Weishu,et al.Excavation –disturbed zone and weaken degree of mechanics properties for rockmass of TGP shiplock slope[J] Chinese Journal of Rock Mechanics and Engineering,2004,23(7):1078-1081.(in Chinese)

[4] ZHOU Liming,XIAO Guoqiang,YIN Jianmin.Measurement and study on rock deformation modulus of power tunnel's loosened zone in Bakun hydropower station[J].Chinese Journal of Rock Mechanics and engineering,2006,25(Supp.2):3971-3975.(in chinese)

[5] HAJIABDOLMAJID V，KAISER P K，MARTIN C D. Modelling brittle failure of rock[J]. International Journal of Rock Mechanics and Mining Sciences. 2002，39(6)：731–741.

DOI: 10.1016/s1365-1609(02)00051-5

[6] DIEDERICHS M S. The 2003 Canadian geotechnical colloquium：mechanistic interpretation and practical application of damage and spalling prediction criteria for deep tunneling[J]. Canadian Geotechnical Journal，2007，44(9)：1 082–1 116.

DOI: 10.1139/t07-033

[7] MogiK1 , Igarashi K1and Mochizuki H1 ,Defomation and Fracture of Rocks under General Triaxial Stress State2Anisotropic Dilatancy1J MateHai Sci1Japan ,1978 ,27 :148～154

[7] Xu Dong Jun ,Geng Nai Guang ,Rule of the Rock Chang along with the Mid principal Stress[J]Journal of Solid Mechanical ,1985 , (1) :72～80

[9] YU Mao-hong. Unified strength theory and its applications[M]. Beilin: Springer, (2004)

[10] ZHANG Chuan-qing, ZHOU Hui, FENG Xia-ting.Numerical format of elastoplastic constitutive model based on the unified strength theory in FLAC3D[J]. Rock and Soil Mechanics, 2008, 26(3): 596–601. (in Chinese)

[11] MA Zong-yuan, LIAO Hong-jian, XIE Yong-li，True triaxial simulation based on unified elastoplastic finite difference method[J] Chinese Journal of Geotechnical Engineering 2010,32（9）：1368-1373

[12] WANG Shuilin，WANG Wei，WU Zhenjun. Study of relationship between evolution of post-peak strength parameters and stress-strain curves of geomaterials[J] .Chinese Journal of Rock Mechanics and engineering, 2010,29（8）：1524-1529(in Chinese)